1. Field of the Invention
The present invention relates to novel beverage compositions and is particularly suitable for preparing beverages of the dietetic type with improved mouthfeel and sweetness qualities. The beverages of the present invention involve compositions composed of at least one food-acceptable hydrocolloidal polysaccharide, a saccharin salt, and an aspartyl phenylalanine methyl ester sweetener.
2. Description of the Prior Art
It is very desirable, for obvious reasons, for beverages to have good mouthfeel characteristics. The presence of different concentrations of suspended and dissolved substances, such as sugars, will often significantly affect mouthfeel. The deletion of sugars in a dietetic beverage where an artificial sweetener is used, consequently leaves a great deal to be desired. It is well known that included principally among the adverse properties of dietetic beverages are a lack of texture and mouthfeel sufficiently similar to that of sugar sweetened beverages. Despite numerous attempts to eliminate the concomitant aftertaste of dietetic beverages, the art has achieved only limited success in attempting to closely approximate the taste, mouthfeel, and texture characteristics of sugar-sweetened beverages.
The beverage composition of the present invention includes a dipeptide sweetener. Aspartyl phenylalanine methyl ester sweeteners are examples of these dipeptide sweeteners which are disclosed in U.S. Pat. No. 3,475,403 and are represented by the following structural formula: ##STR1## wherein X is selected from the group of radicals consisting of: ##STR2## R being a member of the group consisting of hydrogen and a lower alkyl radical, m an integer selected from the group consisting of 0 and 2 and n a positive integer less than three.
The most widely-known dipeptide base sweetener is .alpha.-L-Aspartyl-L-phenylalanine methyl ester (hereinafter referred to as Aspartame). Aspartame has sweetness of good quality and a degree of sweetness about 200 times the sweetness of sucrose. The use of aspartame as a diet sweetener is very widespread.
Unfortunately, however, the aforesaid dipeptide sweeteners have been found to be relatively unstable compounds. For example, aspartyl phenylalanine methyl ester undergoes decomposition or change relatively readily under certain conditions to form a diketopiperazine, causing a significant diminution in sweetening power. When aspartyl phenylalanine methyl ester is admixed with water, it does not dissolve readily but tends to lump, said lumps dissolving with some difficulty. The foregoing considerations have presented substantial problems in preparing the said dipeptide sweeteners in a form such that advantage can be effectively taken of their high sweetening properties while, at the same time, avoiding as much as it is reasonably possible the problems inherent in the solubility and instability characteristics of said dipeptides.
Saccharin is an ingredient commonly employed as a sugar substitute but offers the drawback of having an objectionable bitter, metallic aftertaste. The incidence of off-taste due to saccharin has been reported to be a function of the concentration of the compound. It has further been reported that everyone can be expected to obtain an off-taste from saccharin at some concentration. Combinations of saccharin with such ingredients as pectin or sorbitol, maltose, dextrose, etc. have been tried in hopes of eliminating the aftertaste. Combinations of saccharin and salts of cyclamates have been used as well but none of the aforementioned combinations have achieved the desired result.
Although on a weight for weight basis saccharin at its threshold level of sweetness is about 700 times as sweet as sucrose, at normal use levels it is only 200-400 times as sweet as sucrose. The sweetness of saccharin relative to sucrose decreases as the concentration of saccharin increases. In order to obtain a given increase in sweetness level with saccharin, it is consequently necessary to employ a proportionately greater concentration of saccharin. This increased level of saccharin in turn causes a greater perception of objectionable aftertaste.
Hydrocolloidal polysaccharides, as employed herein, is a term which includes natural gums, modified or synthetic gums and synthetic ethers of polysaccharides.
Gums are high polymer carbohydrates that are insoluble in alcohol and other organic solvents, but generally soluble or dispersible in water. Natural gums are hydrophilic polysaccharides composed of monosaccharide units joined by glycosidic bonds. They occur, for example, in various trees and shrubs in tropical areas, in seaweed, or a phycocolloids (algae). Their chief use is as protective colloids and emulsifying agents in food products and pharmaceuticals.
U.S. Pat. Nos. 2,761,783; 2,876,107; 3,061,445; 3,294,544; 3,413,125; 3,476,571; 3,987,211 and 4,228,198 disclose types of beverages which include in their composition saccharin and a gum. None of the aforementioned patents, however, suggest the use of an aspartyl phenylalanine methyl ester sweetener in the described compositions.
U.S. Pat. Nos. 3,695,898; 3,780,189; 3,934,047; 4,001,455; 4,009,292 and 4,690,827 relate to compositions including aspartame and saccharin but do not disclose the use of a gum in combination therewith.
U.S. Pat. No. 4,051,268 suggests a solid beverage composition, including aspartame and an edible gum but does not describe the use of saccharin in the composition.